726 research outputs found

    Forecast, observation and modelling of a deep stratospheric intrusion event over Europe

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    A wide range of measurements was carried out in central and southeastern Europe within the framework of the EU-project STACCATO (Influence of Stratosphere-Troposphere Exchange in a Changing Climate on Atmospheric Transport and Oxidation Capacity) with the principle goal to create a comprehensive data set on stratospheric air intrusions into the troposphere along a rather frequently observed pathway over central Europe from the North Sea to the Mediterranean Sea. The measurements were based on predictions by suitable quasi-operational trajectory calculations using ECMWF forecast data. A predicted deep Stratosphere to Troposphere Transport (STT) event, encountered during the STACCATO period on 20-21 June 2001, could be followed by the measurements network almost from its inception. Observations provide evidence that the intrusion affected large parts of central and southeastern Europe. Especially, the ozone lidar observations on 20-21 June 2001 at Garmisch-Partenkirchen, Germany captured the evolution of two marked tongues of high ozone with the first one reaching almost a height of 2 km, thus providing an excellent data set for model intercomparisons and validation. In addition, for the first time to our knowledge concurrent measurements of the cosmogenic radionuclides <sup>10</sup>Be and <sup>7</sup>Be and their ratio <sup>10</sup>Be/<sup>7</sup>Be are presented together as stratospheric tracers in a case study of a stratospheric intrusion. The ozone tracer columns calculated with the FLEXPART model were found to be in good agreement with water vapour satellite images, capturing the evolution of the observed dry streamers of stratospheric origin. Furthermore, the time-height cross section of ozone tracer simulated with FLEXPART over Garmisch-Partenkirchen captures with many details the evolution of the two observed high-ozone filaments measured with the IFU lidar, thus demonstrating the considerable progress in model simulations. Finally, the modelled ozone (operationally available since October 1999) from the ECMWF (European Centre for Medium-Range Weather Forecasts) atmospheric model is shown to be in very good agreement with the observations during this case study, which provides the first successful validation of a chemical tracer that is used operationally in a weather forecast model. This suggests that coupling chemistry and weather forecast models may significantly improve both weather and chemical forecasts in the future

    Impressing for Success: A Gendered Analysis of a Key Social Capital Accumulation Strategy

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    Social capital theory assesses the career benefits that accrue to individuals from the stock of relationships they have. Such benefits can be in the form of guidance and advice, access to key projects and assignments and help with setting up business deals. However, when assessing whether such career-enhancing resources are available equally to men and women, we find that gender impacts on the access to and accumulation of social capital. The article seeks to address two key research questions. The first is whether women are aware of the need to accumulate social capital to advance their careers and the second is whether they use impression management techniques in order to assist them in doing this. Findings are reported from a study in an international consulting firm with 19 female consultants. In respect of research question one the findings indicate that women in the sample are aware of the need to accumulate social capital to advance their careers; with particular emphasis being placed on the importance of gaining access to influential sponsors. In respect of research question two, the findings confirm that women in the sample do perceive the necessity to utilise impression management techniques to help them to accumulate social capital. This is done in a defensive way and is linked to ensuring that one is seen as ambitious, likable and available. It is argued that these are key organizational norms, and it is perceived that in order to accumulate social capital, women need to actively work to dispel the negative stereotypes that attach to them because of their gender. The article calls for greater recognition of the impact that masculine organizational cultures have on the career development of women, who not only have to perform at a high level but are also required to expend additional energy conforming to masculine organizational cultures they have had little say in creating

    Willingness to Use a Wearable Device Capable of Detecting and Reversing Overdose Among People Who Use Opioids in Philadelphia

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    Background: The incidence of opioid-related overdose deaths has been rising for 30 years and has been further exacerbated amidst the COVID-19 pandemic. Naloxone can reverse opioid overdose, lower death rates, and enable a transition to medication for opioid use disorder. Though current formulations for community use of naloxone have been shown to be safe and effective public health interventions, they rely on bystander presence. We sought to understand the preferences and minimum necessary conditions for wearing a device capable of sensing and reversing opioid overdose among people who regularly use opioids. Methods: We conducted a combined cross-sectional survey and semi-structured interview at a respite center, shelter, and syringe exchange drop-in program in Philadelphia, Pennsylvania, USA during the COVID-19 pandemic in August and September 2020. The primary aim was to explore the proportion of participants who would use a wearable device to detect and reverse overdose. Preferences regarding designs and functionalities were collected via a questionnaire with items having Likert-based response options and a semi-structured interview intended to elicit feedback on prototype designs. Independent variables included demographics, opioid use habits, and previous experience with overdose. Results: A total of 97 adults with an opioid-use history of at least 3 months were interviewed. A majority of survey participants (76%) reported a willingness to use a device capable of detecting an overdose and automatically administering a reversal agent upon initial survey. When reflecting on the prototype, most respondents (75.5%) reported that they would wear the device always or most of the time. Respondents indicated discreetness and comfort as important factors that increased their chance of uptake. Respondents suggested that people experiencing homelessness and those with low tolerance for opioids would be in greatest need of the device. Conclusions: The majority of people sampled with a history of opioid use in an urban setting were interested in having access to a device capable of detecting and reversing an opioid overdose. Participants emphasized privacy and comfort as the most important factors influencing their willingness to use such a device. Trial Registration: NCT0453059

    Structure–activity relationship of ipglycermide binding to phosphoglycerate mutases

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    Catalysis of human phosphoglycerate mutase is dependent on a 2,3-bisphosphoglycerate cofactor (dPGM), whereas the nonhomologous isozyme in many parasitic species is cofactor independent (iPGM). This mechanistic and phylogenetic diversity offers an opportunity for selective pharmacologic targeting of glycolysis in disease-causing organisms. We previously discovered ipglycermide, a potent inhibitor of iPGM, from a large combinatorial cyclic peptide library. To fully delineate the ipglycermide pharmacophore, herein we construct a detailed structure–activity relationship using 280 substituted ipglycermide analogs. Binding affinities of these analogs to immobilized Caenorhabditis elegans iPGM, measured as fold enrichment relative to the index residue by deep sequencing of an mRNA display library, illuminated the significance of each amino acid to the pharmacophore. Using cocrystal structures and binding kinetics, we show that the high affinity of ipglycermide for iPGM orthologs, from Brugia malayi, Onchocerca volvulus, Dirofilaria immitis, and Escherichia coli, is achieved by a codependence between (1) the off-rate mediated by the macrocycle Cys14 thiolate coordination to an active-site Zn2+ in the iPGM phosphatase domain and (2) shape complementarity surrounding the macrocyclic core at the phosphotransferase–phosphatase domain interface. Our results show that the high-affinity binding of ipglycermide to iPGMs freezes these structurally dynamic enzymes into an inactive, stable complex

    Residual Cx45 and its relationship to Cx43 in murine ventricular myocardium

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    Gap junction channels in ventricular myocardium are required for electrical and metabolic coupling between cardiac myocytes and for normal cardiac pump function. Although much is known about expression patterns and remodeling of cardiac connexin (Cx)43, little is known about the less abundant Cx45, which is required for embryonic development and viability, is downregulated in adult hearts, and is pathophysiologically upregulated in human end-stage heart failure. We applied quantitative immunoblotting and immunoprecipitation to native myocardial extracts, immunogold electron microscopy to cardiac tissue and membrane sections, electrophysiological recordings to whole hearts, and high-resolution tandem mass spectrometry to Cx45 fusion protein, and developed two new tools, anti-Cx45 antisera and Cre(+);Cx45 floxed mice, to facilitate characterization of Cx45 in adult mammalian hearts. We found that Cx45 represents 0.3% of total Cx protein (predominantly 200 fmol Cx43 protein/”g ventricular protein) and colocalizes with Cx43 in native ventricular gap junctions, particularly in the apex and septum. Cre(+);Cx45 floxed mice express 85% less Cx45, but do not exhibit overt electrophysiologic abnormalities. Although the basal phosphorylation status of native Cx45 remains unknown, CaMKII phosphorylates eight Ser/Thr residues in Cx45 in vitro. Thus, although downregulation of Cx45 does not produce notable deficits in electrical conduction in adult, disease-free hearts, Cx45 is a target of the multifunctional kinase CaMKII, and the phosphorylation status of Cx45 and the role of Cx43/Cx45 heteromeric gap junction channels in both normal and diseased hearts merits further investigation
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